1. Field
The disclosure relates, generally, to a method and apparatus, and more particularly, to a method and apparatus for network virtualization and session management applied to a next-generation communication system.
2. Description of the Related Art
In order to meet the increasing demand for wireless data traffic after commercialization of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. The 5G or pre-5G communication systems are also referred to as beyond 4G network communication systems or post LTE systems.
Implementation of a 5G communication system in an ultrahigh frequency (mmWave) band has been considered to achieve high data rates. Technologies such as beamforming, massive MIMO, full dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and large scale antennas for the 5G communication system have been considered to mitigate a path loss of radio waves and to increase a transfer distance of the radio waves in the ultrahigh frequency band.
Further, for system network improvement in the 5G communication system, technology developments have been made for an evolved small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network, device to device communication (D2D), wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMP), and reception interference cancellation.
In addition, in the 5G system, hybrid frequency-shift keying (FSK) and quadrature amplitude modulation (QAM), such as FQAM and sliding window superposition coding (SWSC), which correspond to advanced coding modulation (ACM) systems, as well as filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA), which correspond to advanced connection technologies, have been developed.
On the other hand, in configuring a network slice, the standards for heightening flexibility through configuration of network function virtualization have been discussed. However, in case of such network function virtualization, it is required to perform an operation of a network realistically using a physical entity together, and there has been an increasing demand for effectively solving a control part that is unable to be solved by the operation discussed in the network function virtualization. In particular, since the current process is focused on the process for controlling the virtualization, or it corresponds to a control method in case where only a physical entity exists, there is a need for a process for effectively controlling and managing the same.
Furthermore, in a case of performing a handover of a protocol data unit (PDU) session, a terminal generates a data path for the PDU session toward a target access using a PDU session establishment procedure with respect to the target access, and erases a data path for the existing source access. However, since the terminal in a CM (connection management)-IDLE state should be switched to a CM-CONNECTED state through first performing of a service request or a registration request in order to perform the PDU session establishment procedure with respect to the target access, handover delay and signaling messages frequently occur. Further, if the terminal has not been registered with respect to the target access, it should perform the handover using the PDU session establishment procedure after first performing registration with respect to the target access, and thus the handover delay and signaling messages may frequently occur in the same manner.
Thus, there is a need for a process for effectively performing a handover of a PDU session with respect to the target access through a service request and registration request process.